1. Field of the Invention
This invention relates to a drive frame for a scraper-chain conveyor.
2. Description of the Prior Art
It is known to provide a conveyor drive frame with a drive assembly having a shaft mounted in bearings carried by the two side plates of the drive frame. The shaft passes through, and drivably engages within, a chain drum, which is rotatably mounted between the side plates. The chain drum transfers drive, from a drive unit flanged to one of the side plates to the scraper assembly of the conveyor, via the shaft. Scraper-chain conveyors are used in underground mining operations for removing won mineral material, for example coal, from a longwall working. The drive unit used to drive such a conveyor is very heavy, so the drive frame is subjected to extremely heavy loads. Moreover, a drive unit for the plough (or other winning machine) may also be flanged to one of the side plates of the drive frame, in which case the drive frame is subjected to even greater loads. Such loads may be so great as to bend the drive frame in the region where the chain drum is mounted, this being the weakest region, since it is not possible to reinforce this region with transverse struts or the like. (DE-As No. 1 227 669 and DE-OS No. 2 709 414 describe typical arrangements of this type).
The aim of the invention is to provide a conveyor drive frame which does not suffer from the disadvantages of the known drive frames.